Impactor assembly for printers

ABSTRACT

A plurality of self-restoring equally spaced apart print hammers selectively are driven lineally toward a printing position by continuously rotating impellers having equiangularly spaced radial impelling elements. Each impeller is effective through the agency of a rockable interponent, which is selectively elevated into the path of associated impelling elements upon latching of the armature of an electromagnet, for transmitting impeller force to a corresponding print hammer. An interponent when struck by its impeller is rocked for liberation from armature control, its descent and removal from the path of associated impelling elements being effected by a spring.

United States Patent 1191 1 Babler July 9, 1974 [54] IMPACTOR ASSEMBLY FOR PRINTERS 3,673,956 7/1972 Huber et a1. 101/93 C [75] Inventor: Egon S. Babler, Northbroole, 111. Primary Examiner RObert E. Pulfrey 1 Asslgneei yp Corporaflon, Skokle, Assistant Examiner-Edward M. Coven 3, Attorney, Agent, or Landis A plurality of self-restoring equally spaced apart print [52] US. Cl 101/93 C hammers Selectively are driven lineally toward a Print; [51] Int. Cl B413 9/30 ing position by Continuously rotating impellers having [58] Fleld of Search 101/93 C; 178/3; equiangularly spaced radial i u elements Each 340/1725 impeller is effective through the agency of a rockable interponent, which is selectively elevated into the path [56] References of associated impelling elements upon latching of the UNITED STATES PATENTS armature of an electromagnet, for transmitting impel- 2,766,686 10/1956 Famenko et a1. 101/93 C force to a Corresponding P hammer- An inter- 2,895,41 1 7/1959 Demer et a1. 101/93 C ponent when struck by its impeller is rocked for liber- 2,897,752 8/1959 Malmros et a1. 101/93 C ation from armature control, its descent and removal 3,255,693 6/1966 Eissfeldt et a1 101/93 C fro the path of associated impelling elements being 3,292,531 12/1966 Mutz 101/93 0 ff t d by a Spring 1 3,517,611 6/1970 Fink 101/93 C 3,587,456 6/1971 Jaensc 101/93 C 10 Claims, 10 Drawing Figures PATENIEU JUL 9 1974 PATENTEU 91974 SNEEY 2 OF 6 h j 8 m H, M

MM mm m PAIENTEBM 3.822.641

sum u (If 6 PAIENTEB r 3,822,641

sum E OF 6 IMPACTOR ASSEMBLY FOR PRINTERS BACKGROUND OF THE INVENTION The present invention relates to signal responsive impact printers. More particularly, the invention relates to impacter assemblies for impact printers.

In printers with which the present invention is concerned, printing is done on the fly at high speeds. In one class of such printers, character dies or type may be conveyed on a continuously moving endless carrier past print hammers. To maximize printing speed in response to output capability of known automatic date transmission systems, the capability of the printing apparatus to respond to availability of data must be maximized.

Ideally suited for developing impact forces in said class of printers, because of the high level of timing accuracy for print hammer control, are impelling means of the type disclosed in U.S. Pat No. 2,927,960, issued to W. P. Byrnes, Mar. 8, 1960. However, the mechanical inertia of the impelling means as well as of its print hammers limits the speed of printing response, in apparatus according to said patent, to a level which is incompatible with modem requirements, namely, an optimum rate for handling the output from a bufier storage, for example, between incoming data and a printing mechanism.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a novel impact printer.

It is another object of the invention to provide novel impeller means in an impact printer with a radial impeller.

It is a further object of the present invention to maximize printing speed in an impact printer having radial impellers.

It is an additional object of the invention to minimize mechanical inertia of impelled members in an impact printer of the indicated class.

To effect the foregoing, and other objects of the invention which will become apparent from the ensuing detailed descriptions, means are provided for removing armature control of an interponent in an impact printer of the type wherein an interponent responds to an armature by moving into the path of a rotating impeller for intermittently transmitting force from the impeller to a print hammer.

Objects of the invention are also effected in an impact printer having a hammer mounted for intermittent lineal movement toward a printing condition in response to rotation of an impeller whose torque is intermittently translated to lineal force for driving the hammer. The translating means is comprised of an interponent having a projected condition in the impeller path for force transmission and a withdrawn condition out of the path of said impeller. An armature for controlling said interponent is arranged for movement between a first position in which the interponent is in its projected condition and a second position spaced below said first position. Means are provided for liberating the interponent from armature control following armature movement to said first position and for returning the interponent to armature control following armature movement to said second position.

BRIEF DESCRIPTION OF THE DRAWINGS In the ensuing detailed description of the drawings, reference is had to the accompanying drawings on which:

FIG. 1 is a perspective view of an impact printer embodying one form of the invention, parts being broken away and parts omitted for the purpose of illustration;

FIG. 2 is a vertical sectional view of said printer according to the line 2-2 of FIG. 1.

FIG. 3 is a view of said printer in a broken horizontal plane according to the line 33 of FIG. 2, parts broken out for the purpose of illustration;

FIG. 4 is a vertical sectional view of the printer according to the line 44 of FIG. 2, parts broken out for the purpose of illustration;

FIG. 5 is a detailed view of a guide structure for print hammers of said printer and in a vertical plane according to the line 55 of FIG. 2, some of the hammers omitted;

FIGS. 6A-6D are views similar to a portion of FIG. 2, and each to the other, however, showing impelling means of said printer in alternate conditions; and

FIG. 7 is an enlarged side elevation of an exemplary print hammer in said printer.

DETAILED DESCRIPTION OF THE INVENTION Referring now to FIG. 1 of the drawings, the impact printer, generally indicated 10, is of the class having a pair of spaced apart pulleys 14 and 16 about which an endless carrier 12 is entrained for translocating a plurality of dies 17 (FIG. 7) by movement in a circuitous path. The dies are carried on the front faces of uniformly dimensioned pallets 18 which are uniformly spaced apart axially of the carrier. When the dies comprise alphanumeric characters, two or more successive fonts axially of carrier 12 may enable longer line output. Carrier 12 and pallets 18 together with their mountings may be substantially as shown and described in the copending application of Francis E. Huntoon and James F. Kearney, Ser. No. 208,198, filed Dec. 15, 1971, and assigned to the assignee of the present application, now U.S. Pat. No. 3,742,848, issued on July 3, 1972. In accordance with said copending application, the plane in which parallel axes of pulleys l4 and 16 are disposed and the section 20 of web 22 on which printing is about to occur are orthogonally disposed. Such arrangement generates a loop in the carrier with an upper or printing course 21 and a lower or return course 23 which are disposed in a plane which is substantially parallel to the plane of web section 20.

In the illustrated embodiment, pulley 14 is an idler sheave while pulley 16 is a drive sheave secured to a shaft 24. Driving torque continuously is transmitted to shaft 24 from an operating prime mover means, herein shown as a motor 26, through a drive train comprised of: a worm gear 28 securedto the shaft 30 of the motor; a gear 34 operably enmeshed with worm gear 28 and secured on one endportion of a continuously drivable impeller shaft 32; a worm gear 36 carried from the other end portion of impeller shaft 32; and a gear 38 operably meshed with worm gear 36 and secured on shaft 24 in spaced relationship with pulley 16.

A segment 40 of ribbon 42 is disposed in a plane substantially parallel to carrier course 21 between and spaced slightly from face 41 of web section 20 and the pallets 18 supported from said last course. The ribbon is trained about a plurality of ribbon guides 44 which are spaced apart such that the ribbon assumes a generally rectangular configuration in a horizontal plane. Opposed end portions of the ribbon are secured to a pair of adjoining ribbon spools 46 and 48 which alternately function for ribbon supply and accummulation. They alternately are driven in opposite angular directions, by a spool control mechanism 50, the details of construction of which form no part of the present invention. The mechanism 50 is connected to motor 26 by a pulley wheel 52, disposed in a common plane with spools 46 and 48. It is secured on an end portion 54 of shaft 24 for driving spool control mechanism 50 through a pulley belt 56.

A clutch 58, which may be conventional, is mounted for releaseably securing a split shaft section 60 to the shaft 24 from which said section extends axially. Selective actuation of mounted. (not the clutch may be effected through logic (not shown) which may be conventional and the details of construction of which form no part of the invention. Thereupon, operating means, generally designated 62, advances web 22, in the direction shown by arrow 63 a line at a time. Such advancement results from incremental rotation of a worm gear 64 which is secured to shaft section 60 in mesh with a gear 66. A stub shaft 68 on which the last gear is secured transfers torque from gear 66 to a driving sheave 70 also secured to said stub shaft. A pulley belt 72 operably is trained about sheave 70 and a driven sheave 74 for intermittently angularly moving a cylindrical roller 76 coaxially secured on a shaft 78 on which said sheave 74 is also maounted. Roller 76 is disposed transversely of and adjacent to the path of web movement for frictionally engaging web 22 and in cooperation with other components (not shown), intermittedly drawing said web from its supply source (nt shown) about a guiding cylinder 82, as said web is advanced.

In accordance with the invention, impelling means comprises an array of radially symmetrical impellers 84 (only representative ones of which are shown in FIG. 1). Each impeller is comprised of a plurality of radial, equiangularly spaced arms or impelling elements 83. The impellers are concentrically secured to shaft 32 for rotation therewith, and are axially or horizontally spaced such that each is disposed in substantially horizontal alignment with a printing station on an imaginary line extending horizontally across web section 20. Opposed end portions of the shaft 32 are journalled in spaced apart vertical side members 85 (only one is shown in FIG. 2) of the chassis 87 of printer 1(1). In a preferred embodiment of the present invention, the impellers are arranged in the manner which i have disclosed in copending application Ser. No. 268,236, filed contemporaneously herewith.

Impacter means for printing comprise a plurality of hammers 86 (only some of which are shown in FIG. 1) disposed behind back face 80 (FIG. 2) of web section 20. Each hammer is aligned with the others in a horizontal array (FIG. 9) parallel to the alignment of impellers 84. Each hammer also is aligned with, though Spaced from, and disposed out of the path of movement of an associated impeller by which it can be driven in a lineal path, perpendicularly to web section 20, between a normal, untensioned, or non-printing position (FIG. 1) and a printing position (FIG. 6C) against said back face (FIG. 2).

The hammers 86 and the dies 17 on pallets 18 in course 21 are disposed at a common horizontal level (FIG. 7) and said pallets and their dies when translocated move in a path parallel to the hammer array. Thereby, each pallet and groups thereof can be moved successively into printing positions in horizontal alignment with successive hammers and groups thereof. The force generated by each impeller for urging said web section, ribbon segment 40 and any aligned dies 17 into contact is of sufficient magnitude for printing by forming an image of each such die onweb face 41.

A horizontal bumper, inthe form of a rod 88 is disposed parallel to shaft 32, has opposed ends secured in the chassis 87. Said rod extends through horizontally aligned slots 90 in the bodies 94 of hammers 86 for limiting hammer movement. In the preferred embodiment of the invention herein, impact forces of said hammers are controlled by means which I have disclosed in copending application Ser. No. 268,237, filed contemporaneously herewith.

The agency through which each impeller 84 moves its hammer 86 comprises an interponent 92 (FIGS. 2 and 6A-6D). Each of the latter is elongated or armlike, having a general upright aspect; and each interponent is aligned and operatively associated with one hammer 86 and one impeller 84. The interponents are disposed in generally horizontal alignment; and each can be individually positioned in: (l) a first or upper position (FIGS. 6A and 6B) in which it is in a projected condition, with its upper free end portion 98 disposed in the path of movement of impelling elements 83 for transmitting force from its impeller 84 to an aligned hammer 86, in consequence of which printing occurs; or (2) a lower, non-printing, or second position (FIGS. 2 and 6D) in which said interponent has fallen and its free end portion 98 has been removed from the impeller path.

Each hammer is elongated in a direction of its path of movement, and projecting from forward and rear portions of its body 94 has a relatively wide impacting head 95 and a narrower tail section 96. The free end face of the latter addresses the upper end portion 98 of an associated interponent 92.

An upper wall 100 (FIG. 2) of chassis 87 defines the base of a chamber 102 behind web section 20. Hammers 86 are slideably mounted in said chambers against a transverse bearing bar 107 (FIG. 2) mounted on wall 100. A chassis plate 104, preferably fabricated from brass or the like, has portions disposed in bearing engagement with hammers 86 and extends in a horizontal plane as a roof or cover for a chamber 102. A flange 106 (FIG. 5) depending from plate 104 is slotted as at 108 to provide a plurality of horizontally aligned verti cal guides and between which hammers 86 are reciprocative.

A leaf spring 110, associated with each hammer 86, is included in hammer driving means and has a lower end portion 112 which is rigidly secured to a front chassis plate 1141. The upper end portion 116 of each spring is engaged in a downwardly opening slot 118 in each hammer head 95. Each spring has a relatively untensioned condition (FIGS. 2'and 6A) duringv which its hammer is in its rearward or most remote non-printing position, and a most tensioned condition (FIG. 6C)

during printing, for urging or restoring its hammer to non-printing position.

To enable maximization of the size of the force transferring surfaces of each assembly of an associated impeller 84, a hammer 86 and an interponent 92, a plurality of shims 97 (FIGS. 2 and 4) are disposed between the impellers. The shims are circular, being concentric with shaft 32, each shim having a radius of sufficient magnitude for guiding the associated hammers and interponents during operation and assuring proper spacing during assembly of the apparatus.

Each interponent 92 is a discrete member disconnected from or unfastened to any other structure; though, intermittently each interponent will be engaged with certain structure to be described, and is controlled by a corresponding one of a plurality of assemblies 122, each comprised of a magnetically latchable armature 124 and an electromagnet 126. Each illustrated electromagnet comprises a pair of electrically interconnected windings or coils which respectively are mounted about respective arms 120 (FIG. 3) of a pair thereof comprising a core member 121 (FIG. 6A). The core members, and therefore their windings, are uniformly spaced apart and disposed horizontally in a pair of parallel arrays, one of which is aligned adjacent the front chassis plate 1 14 and the other of which is aligned along a rear chassis plate 128 (FIGS. 2 and 3).

Each core member has an upwardly projecting anchoring lug or stud 123 (FIG. 2 left) which is firmly secured in a respective one of a plurality of holes 125 in chassis wall 100. Said holes are aligned in parallel sets, each set extending along a respective one of the chassis plates 114 and 128.

By reason of the foregoing, electromagnets 126 are disposed in a first straight array, set or bank 130 (FIG. 3) adjacent and parallel to rear chassis plate 128 and in a second array, set or bank 132 adjacent and parallel to chassis plate 114 and in a position opposed to bank 130. However, each core member 121 in one of the banks 130 and 132, though equally spaced from adjoining core members, is offset horizontally from the corresponding core member in the opposed bank by a distance equal to half the spacing between adjacent core members, as shown in FIG. 3.

Each armature 124 has an outer portion 134 which is disposed adjacent one of the chassis plates 128 and 114 according to the bank 130 and, 132 with which such armature is associated. Each armature also has an inner portion 136 (FIGS. 2 and 3) which terminates in a flat stand 138 (FIG. 4). The arrangement of the armatures in offset rows 130 and 132 is such that all of the stands 138 are disposed in general alignment, horizontally, with each armature being vertically aligned with an associated one of said impellers 84.

Chassis wall 100 has an elongated horizontal slot 140 (FIG. 2) from which the upper end portions 98 of interponents 92 project upwardly. A front horizontally extending hanger plate 142 and a rear horizontally extending hanger plate 144 depend in vertical aspect and in parallel association from said wall 100. The hanger plates are adjustably secured to said wall by a plurality of fasteners 143 for varying the width of a horizontal guide slot or interponent passage 146, which is coextensive with slot 140, about a medial portion of interponents 92. An elastomeric or spring rod 148 is secured in an elongated horizontal channel on the inner wall of the front hanger plate 142 in engagement with a medial part of all the interponents 92. Rod 148 provides a fulcrum or axis member disposed transversely of said interponents and about which said interponents are rockable with the limits of slot (compare FIGS. 6A, 6B, and 6C).

A horizontally elongated channel 150 (FIGS. 2, 3, and 4), U-shaped in cross-section, has upper end portions of its opposed sides 152 and 154 suitably secured to the outside surfaces of hanger plates 142 and 144 such that the closed end portion of said channel is spaced from the lower ends of said hanger plates. Moreover, channel 150 is disposed medially of the electromagnets 126 of banks 130 and 132, and said channel defines a chamber 151 which extends longitudinally of the alignment of the impellers 84 and accordingly, of the interponents 92. Channel sides 152 and 154 are slotted, respectively, the slots 156 in side 152 and the slots 158 in side 154 being spaced apart in horizontal alignment. Armature stands 138 are disposed in the lower end portion of chamber 151 with the armatures in bank 130 passing through slots 158 in channel side 154 and the armatures in bank 132 passing through slots 156 in channel side 152.

An elongated elastomeric bumper 160 extends along the bottom of channel 150 below and parallel to the general alignment of the stands 138. The bumper is retained in a support base 162 which is secured along the bottom of the channel by means of a plurality of fasteners such as the screws 164, (FIGS. 2 and 4).

An expansion spring 166 (FIGS. 2 and 6A-6D) having one end anchored about a chassis supported lug or ear 168 and an opposite end connected to an extension 169 from each armature 124 biases its associated armature against bumper 160 (FIG. 2) and away from a magnetically attracted or latched position (FIGS. 6A-6D).

Each hammer 86, through the agency of an interponent 92 will be driven to a printing position upon actuation of the corresponding armature 124. Means for liberating or removing the armature from, each interponent comprises an associated spring 170. Each of said springs is arranged for urging an associated interponent 92 downwardly, to the position shown in FIG. 2, where the upper end portion 98 is retracted out of the path of its associated impeller 84. Ensuing description will elaborate this feature. Each of said springs has aforward bent end portion 172 with a hairpin curve and a rear or arcuately bent end portion 174 bent defining an enlarged reverse curve terminating in an offset forwardly projecting straight end segment 176.

Channel side 152 has a plurality of horizontally aligned vertical slots 178 (FIGS. 2 and 4), each of said slots aligned with and superposed relative to a slot 156 and associated with one of said interponents 92. Each of the interponents 92 has a medial slot 180 (FIGS. 4 and 6B) disposed below the position at which said interponent is engaged by axis rod 148. Each spring passes through a corresponding slot 180 such that its connecting and upper bearing portion 182 passes below the upper margin of such slot 180 and its end segment 176 engages the interponent at the lower margin of a corresponding slot 180 and biases a corresponding interponent downwardly. The arcuately bent portion 174 of each spring passes through the corresponding slot 158, and its hairpin-curved portion 172 passes through associated slot 178. A spring tensioning or retaining rod 184 parallel to the alignment of stands 138 extends longitudinally of channel side 152 against the outside of which it is held by entrainment thereabout of the hairpin-curved portions 172 of all of springs 170. A rearwardly projecting and extension 186 of each of said spring bent end portions 172 bears against side 152 at the lower margin of a corresponding slot 178 and tensions such spring against the lower ends of hanger plates 142 and 144. The parts are proportioned such that when the springs 170 are in their most relaxed conditions (FIGS. 2 and 6D), spring curve 172 and end portion 174 are slightly tensioned.

OPERATION OF THE PRINTER Printer 10 is adapted as a line-at-a-time printer; that is to say, a plurality of characters simultaneously may be printed transversely of the path of web movement on a line across web section 20. This requires a facility for selective operation simultaneously of a plurality of armatures 124. Any suitable logic (not shown and forming no part of the present invention) which may be conventional may be employed for energizing selected electromagnets 126. Inasmuch as the assemblies including impellers 84 are substantially identical, a description of the operation of one will stand for the description of the operation of all, an operational cycle of an impeller assembly being illustrated in FIGS. 2 and 6A-6D.

FIG. 2 shows the rest or non-printing position of the two interponents 92 illustrated, with the electromagnets de-energized. At the start of a printing cycle for the particular interponent 92 and hammer 86 shown at the right in FIG. 2 (and in FIGS. 6A-6D), the corresponding electromagnet 126 in the right bank 132 is energized; its armature 124 will be rocked, magnetomotively, counter to bias of its spring 166, clockwise, to a latched position (FIGS. 6A6D). A corresponding energization of an electromagnet in the left bank 130 will result in counterclockwise movement of its armature. correspondingly, an affected stand 138 will move upwardly (from its FIG. 2 position) to the position of FIG. 6A. Upon elevation of the stand 138, interponent end portion 98 becomes thrust into its first position or projected condition, preferably between a pair of adjoining impelling elements 83 (FIG. 6A) against the return bias of spring 170 which thereby becomes tensioned by compression. Enusingly, the upwardly thrust upper end portion 98 will be engaged (FIG. 68) by a circuitously traveling impelling element 83 and rocked about rod 148 from its first angular aspect (FIG. 6A), during which its lower end portion 99 is engaged with stand 138, successively: 1) past an intermediate or erect angular aspect (FIG. 6B), and thence (2) to its second angular aspect (FIG. 6C) during which said end portion 99 is disengaged from its stand 138.

The parts are proportioned such that, when the interponent has been rocked to its erect aspect (FIG. 68), it engages the corresponding hammer 86, its interponent thus being engaged by the impeller; at which time, the hammer and the impeller become coupled through the interponent to effect momentum transfer and translation of impeller torque into a lineal force for printing. The forward face 190 of each interponent end portion 98, and a rear face 192 of each hammer 86 are flat, the rear face 192 being disposed in a vertical plane. This insures a most efficient force transfer from impeller 84 to hammer 86. The mass of each hammer is such that, almost immediately following interponenthammer contact, the hammer will fly forwardly (FIG. 6C for printing against the bias imposed by spring 110. Simultaneously, its interponent will be rocked to its second aspect, its mass being such that its upper end portion 98 will move forwardly away from the impelling element 83 (FIG. 6C).

Immediately thereupon, heretofore tensioned spring 170, which is included in means for removing or liberating the interponent from armature control, releases its tension, urging the interponent, while in its second angular aspect, out of the path of impeller movement and beyond its armature 124 (FIG. 6D). The parts are proportioned such that the interponent 92 will be removed from the path of impeller motion before its hammer 86 is restored by spring to its normal condition. Thereby, the interponent, liberated from annature 124, is saved from being trapped by the hammer and the moving impeller and is free to and will move to its lower position, even though (as in FIG. 6D) armature 124 has not become unlatched. The significance of the feature of loss of armature control of the interponent is highlighted when considering the following:

Assume that interponent 92 was at all times under the control of its armature and was in a projected position. Assume further that, following force transfer, the magnetic flux field latching its armature failed to collapse or collapsed too slowly. In such event, the interponent would again be struck, undesirably to drive hammer 86 toward a printing position.

Upon de-energization of a magnet 126 its flux field will collapse to release the magnetic latch of an armature 124. Responsively, said armature, if in bank 132, will rock counterclockwise from its position of FIG. 6D to its position of FIG. 2 as its spring 166 releases tension. Thereupon, under impetus of spring 170 an interponent 92 of bank 132 which is in withdrawn position will rock counterclockwise from its position of FIG, 6D to its position of FIG. 2 for restoring its lower end portion to its stand 138. To prevent restoration of the interponent to its first angular aspect before its armature is released from magnetic latch, the armature has an abutment 194 (FIG. 6D) which holds the interponent in its second angular aspect while it is in its withdrawn position.

As many modifications in the described construction could be conceived, and as many widely different embodiments could be made without departing from the spirit and scope of the claims, it is intended that all matter contained in the accompanying specification shall be considered as illustrative only and not in a limiting sense.

I claim: 1. In an impact printer of the type having a hammer mounted for lineal movement toward a printing position in response to lineal forces intermittently transmitted from a rotating impeller, the improvement in means for intermittently translating impeller torque to lineal force for driving said hammer comprising:

a frame; an interponent, having an upper end portion and a lower end portion; v

means for mounting the interponent in the frame so that the interponent is movable between (1) a projected position in which the upper end portion of the interponent is engaged by the rotating impeller to directly translate the impeller torque into a lineal force for driving the hammer toward the printing position, and (2) a withdrawn position in which the upper end portion is not engaged by the impeller;

an armature; means for movably mounting the armature in the frame in a position engageable with the lower end portion of the interponent;

means for moving the armature between (1) a first position in which the interponent is in the projected position and (2) a second position below the first position, the armature mounting means being arranged with respect to the interponent so that the armature is engaged with the lower end portion of the interponent while the armature moves from the second to the first position and is disengaged therefrom while the armature moves from the first to the second position; and

means for moving the interponent, after engagement with the impeller, from the projected position to the withdrawn position independently of the armature and for again engaging the lower end portion of the interponent with the armature when the interponent has been returned to the withdrawn position and the armature has returned to the second position.

2. A combination according to claim 1, wherein the mounting means for the interponent includes an axis member secured to the frame and extending transversely of the interponent between the upper and lower end portions of the interponent, the interponent mounting means being further arranged so that the interponent is movable between a first angular position in contact with the axis member and a second angular position out of contact with the axis member, and so that engagement of the impeller with the interponent moves the interponent from the first angular position to the second angular position.

3. A combination according to claim 2 wherein the means for moving the interponent further comprises a spring for urging the interponent from the projected position when the interponent is in the second angular position to the withdrawn position.

4. A combination according to claim 3 wherein the spring extends through a medial opening in the interponent and is biased against the frame to urge the interponent from the second angular position to the first angular position.

5. A combination according to claim 4 wherein the spring further comprises:

a first end portion disposed in the medial opening in the interponent and biased against the frame;

a second end portion spaced from the first end portion and disposed in the medial opening so that the spring is compressed as the interponent moves from the withdrawn position toward the projected position; and

an arcuate medial portion coupling the first and second end portions and engaging the interponent to urge the interponent to the first angular position from the second angular position when the interponent is in the withdrawn position.

6. A combination according to claim 2 wherein the interponent-mounting means is further arranged so that 1) the upper end portion of the interponent in the projected position and the first angular position is in the path of the impeller but is spaced from the hammer and (2), upon engagement with the rotating impeller, the interponent moves from the first angular position to the second angular position and couples the impeller to the hammer to translate impeller torque to linear force.

7. A combination according to claim 6 wherein the axis member comprises a fulcrum of elastomeric material, and the interponent-mounting means is further arranged so that the interponent rocks about the fulcrum as it moves from the first to the second angular position.

8. In an impact printer of the type having a hammer mounted for lineal movement toward a printing position in response to lineal forces intermittently transmitted from a rotating impeller, the improvement in means for intermittently translating impeller torque to lineal force for driving said hammer comprising:

a frame; an interponent, having an upper end portion and a lower end portion; means for mounting the interponent in the frame so that the interponent is movable between (1 a pro jected position in which the upper end portion of the interponent is engaged by the rotating impeller to directly translate the impeller torque into a lineal force for driving the hammer toward the printing position, and (2) a withdrawn position in which the upper end portion is not engaged by the impeller; an armature; means for movably mounting the armature in the frame in a position engageable with the lower end portion of the interponent; means for moving the armature between (1) a first position in which the interponent is in the projected position and 2) a second position below the first position, the armature mounting means being arranged with respect to the interponent so that the armature is engaged with the lower end portion of the interponent while the armature moves from the second to the first position and is disengaged therefrom while the armature moves from the first to the second position; and means for moving the interponent, after engagement with the impeller, from the projected position to the withdrawn position independently of the armature and for again engaging the lower end portion of the interponent with the armature when the interponent has been returned to the withdrawn position and the armature has returned to the second position; the armature further including: means for supporting the lower end portion of the interponent as the armature moves from the second position to the first position thereby moving the interponent from the withdrawn position to the projected position; and means for preventing engagement of the lower end portion of the interponent with the engaging and supporting means as the armature moves from the first position to the second position so that the interponent is movable from the projected position to the withdrawn position independently of the armature movement. 9. A combination according to claim 8 wherein the means for supporting comprises a raised stand on the armature.

10*. A combination according to claim 9 wherein the means for preventing engagement comprises a side on the raised stand, the stand bearing against a side on the lower end portion of the interponent as it moves from nd position so that engagement of the lower end portion with the raised stand is prevented until the armature is in the second position and the interponent is in the projected position to the withdrawn position and as the withdrawn Position- Disclaimer 3,822,641.-Eg0n S. Babler, Northbrook, Ill. IMPACTOR ASSEMBLY FOR PRINTERS. Patent dated July 9, 1974. Disclaimer filed Jan. 30, 1981, by the assignee, Teletype Corp. Hereby enters this disclaimer to claims 1, 8, 9 and 10 of said patent.

[Official Gazette April 7, 1981.] r 

1. In an impact printer of the type having a hammer mounted for lineal movement toward a printing position in response to lineal forces intermittently transmitted from a rotating impeller, the improvement in means for intermittently translating impeller torque to lineal force for driving said hammer comprising: a frame; an iNterponent, having an upper end portion and a lower end portion; means for mounting the interponent in the frame so that the interponent is movable between (1) a projected position in which the upper end portion of the interponent is engaged by the rotating impeller to directly translate the impeller torque into a lineal force for driving the hammer toward the printing position, and (2) a withdrawn position in which the upper end portion is not engaged by the impeller; an armature; means for movably mounting the armature in the frame in a position engageable with the lower end portion of the interponent; means for moving the armature between (1) a first position in which the interponent is in the projected position and (2) a second position below the first position, the armature mounting means being arranged with respect to the interponent so that the armature is engaged with the lower end portion of the interponent while the armature moves from the second to the first position and is disengaged therefrom while the armature moves from the first to the second position; and means for moving the interponent, after engagement with the impeller, from the projected position to the withdrawn position independently of the armature and for again engaging the lower end portion of the interponent with the armature when the interponent has been returned to the withdrawn position and the armature has returned to the second position.
 2. A combination according to claim 1, wherein the mounting means for the interponent includes an axis member secured to the frame and extending transversely of the interponent between the upper and lower end portions of the interponent, the interponent mounting means being further arranged so that the interponent is movable between a first angular position in contact with the axis member and a second angular position out of contact with the axis member, and so that engagement of the impeller with the interponent moves the interponent from the first angular position to the second angular position.
 3. A combination according to claim 2 wherein the means for moving the interponent further comprises a spring for urging the interponent from the projected position when the interponent is in the second angular position to the withdrawn position.
 4. A combination according to claim 3 wherein the spring extends through a medial opening in the interponent and is biased against the frame to urge the interponent from the second angular position to the first angular position.
 5. A combination according to claim 4 wherein the spring further comprises: a first end portion disposed in the medial opening in the interponent and biased against the frame; a second end portion spaced from the first end portion and disposed in the medial opening so that the spring is compressed as the interponent moves from the withdrawn position toward the projected position; and an arcuate medial portion coupling the first and second end portions and engaging the interponent to urge the interponent to the first angular position from the second angular position when the interponent is in the withdrawn position.
 6. A combination according to claim 2 wherein the interponent-mounting means is further arranged so that (1) the upper end portion of the interponent in the projected position and the first angular position is in the path of the impeller but is spaced from the hammer and (2), upon engagement with the rotating impeller, the interponent moves from the first angular position to the second angular position and couples the impeller to the hammer to translate impeller torque to linear force.
 7. A combination according to claim 6 wherein the axis member comprises a fulcrum of elastomeric material, and the interponent-mounting means is further arranged so that the interponent rocks about the fulcrum as it moves from the first to the second angular position.
 8. In an impact printer of the type having a hammer mounTed for lineal movement toward a printing position in response to lineal forces intermittently transmitted from a rotating impeller, the improvement in means for intermittently translating impeller torque to lineal force for driving said hammer comprising: a frame; an interponent, having an upper end portion and a lower end portion; means for mounting the interponent in the frame so that the interponent is movable between (1) a projected position in which the upper end portion of the interponent is engaged by the rotating impeller to directly translate the impeller torque into a lineal force for driving the hammer toward the printing position, and (2) a withdrawn position in which the upper end portion is not engaged by the impeller; an armature; means for movably mounting the armature in the frame in a position engageable with the lower end portion of the interponent; means for moving the armature between (1) a first position in which the interponent is in the projected position and (2) a second position below the first position, the armature mounting means being arranged with respect to the interponent so that the armature is engaged with the lower end portion of the interponent while the armature moves from the second to the first position and is disengaged therefrom while the armature moves from the first to the second position; and means for moving the interponent, after engagement with the impeller, from the projected position to the withdrawn position independently of the armature and for again engaging the lower end portion of the interponent with the armature when the interponent has been returned to the withdrawn position and the armature has returned to the second position; the armature further including: means for supporting the lower end portion of the interponent as the armature moves from the second position to the first position thereby moving the interponent from the withdrawn position to the projected position; and means for preventing engagement of the lower end portion of the interponent with the engaging and supporting means as the armature moves from the first position to the second position so that the interponent is movable from the projected position to the withdrawn position independently of the armature movement.
 9. A combination according to claim 8 wherein the means for supporting comprises a raised stand on the armature.
 10. A combination according to claim 9 wherein the means for preventing engagement comprises a side on the raised stand, the stand bearing against a side on the lower end portion of the interponent as it moves from the projected position to the withdrawn position and as the armature moves from the first position to the second position so that engagement of the lower end portion with the raised stand is prevented until the armature is in the second position and the interponent is in the withdrawn position. 